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authorWang, Yalin <Yalin.Wang@sonymobile.com>2015-02-12 02:24:51 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2015-02-12 04:06:00 +0300
commit56873f43abdcd574b25105867a990f067747b2f4 (patch)
treebe55c69ee61da7b4e10e46c89e62a2ca68adaf81 /include
parent1d148e218a0d0566b1c06f2f45f1436d53b049b2 (diff)
downloadlinux-56873f43abdcd574b25105867a990f067747b2f4.tar.xz
mm:add KPF_ZERO_PAGE flag for /proc/kpageflags
Add KPF_ZERO_PAGE flag for zero_page, so that userspace processes can detect zero_page in /proc/kpageflags, and then do memory analysis more accurately. Signed-off-by: Yalin Wang <yalin.wang@sonymobile.com> Acked-by: Kirill A. Shutemov <kirill@shutemov.name> Cc: Konstantin Khlebnikov <koct9i@gmail.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include')
-rw-r--r--include/linux/huge_mm.h12
-rw-r--r--include/uapi/linux/kernel-page-flags.h1
2 files changed, 13 insertions, 0 deletions
diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
index ad9051bab267..f10b20f05159 100644
--- a/include/linux/huge_mm.h
+++ b/include/linux/huge_mm.h
@@ -157,6 +157,13 @@ static inline int hpage_nr_pages(struct page *page)
extern int do_huge_pmd_numa_page(struct mm_struct *mm, struct vm_area_struct *vma,
unsigned long addr, pmd_t pmd, pmd_t *pmdp);
+extern struct page *huge_zero_page;
+
+static inline bool is_huge_zero_page(struct page *page)
+{
+ return ACCESS_ONCE(huge_zero_page) == page;
+}
+
#else /* CONFIG_TRANSPARENT_HUGEPAGE */
#define HPAGE_PMD_SHIFT ({ BUILD_BUG(); 0; })
#define HPAGE_PMD_MASK ({ BUILD_BUG(); 0; })
@@ -206,6 +213,11 @@ static inline int do_huge_pmd_numa_page(struct mm_struct *mm, struct vm_area_str
return 0;
}
+static inline bool is_huge_zero_page(struct page *page)
+{
+ return false;
+}
+
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
#endif /* _LINUX_HUGE_MM_H */
diff --git a/include/uapi/linux/kernel-page-flags.h b/include/uapi/linux/kernel-page-flags.h
index 2f96d233c980..a6c4962e5d46 100644
--- a/include/uapi/linux/kernel-page-flags.h
+++ b/include/uapi/linux/kernel-page-flags.h
@@ -32,6 +32,7 @@
#define KPF_KSM 21
#define KPF_THP 22
#define KPF_BALLOON 23
+#define KPF_ZERO_PAGE 24
#endif /* _UAPILINUX_KERNEL_PAGE_FLAGS_H */